Tar files are files which contain a collection of other files, similar in idea to .zip files. Since the submission system used by the undergrad only allows one file to be submitted per student, the usual way to submit many files is to put them into a single tar file and then submit the tar file. This page describes how to manipulate tar files and submit them to the assignment submission system.

Manipulating tar files

• Creating a tar file
  
  • To create a tar file, you can use the command:

    tar -cvf tarfile.tar file1 file2 file3 ...
    

    where tarfile.tar is the name of the tar file to create, and file1 file2 file3 ... is a space-separated list of files and/or directories to put into tarfile.tar. The tar program will print a list of all the files which have been put into the newly created tar file.

  • For example,

    tar -cvf ppass1.tar String.h String.cc
    

    creates a tar file called ppass1.tar which contains the two files String.h and String.cc.

  • You can use the shell wildcard "*" (without the quotes) to match any characters. For example, the following situation is identical to the above example because the only files in the current directory which start with "String." are String.h and String.cc (bold text is typed by the user).

    bash$ ls String.*
    String.h String.cc
    bash$ tar -cvf ppass1.tar String.*
    String.h
    String.cc
    

  • ALWAYS REMEMBER TO SPECIFY THE NAME OF THE TAR FILE! The tar program will not warn you if try to create a tar file which already exists, it will simply overwrite it. This is very dangerous if you forget to specify the name of the tar file to create, and just list the files you want to add, because it means that the first file you specify will actually be overwritten by the tar program. For example, consider what would happen if the following was accidentally typed:

    tar -cvf String.h String.cc
    

    The user has forgotten to specify the name of the tar file as ppass1.tar, but the tar program doesn't know that. Instead, it creates a tar file named String.h (deleting whatever is inside the String.h file) which contains only the String.cc file. Needless to say, this is very bad if you didn't want to destroy your original String.h file.

  • It's possible to add files to a tar file and update files already in a tar file, but it's generally easier and safer to create tar files from scratch as described above.

• Listing the contents of a tar file
  
  • To list the contents of a tar file, you can use the command:

    tar -tvvf tarfile.tar
    

    where tarfile.tar is the name of the tar file to list.

  • For example,

    bash$ tar -tvvf ppass1.tar
    -rw-r--r-- kev/bstaff     2378 Dec 22 22:40 2001 String.cc
    -rw-r--r-- kev/bstaff      194 Dec 22 22:40 2001 String.h
    

• Extracting the contents of a tar file
  
  • To extract the contents of a tar file, you can use the command:

    tar -xvf tarfile.tar
    

    where tarfile.tar is the name of the tar file to extract. The files will be extracted into the current directory.

  • For example,

    bash$ ls
    ppass1.tar
    bash$ tar -tvvf ppass1.tar
    -rw-r--r-- kev/bstaff     2378 Dec 22 22:40 2001 String.cc
    -rw-r--r-- kev/bstaff      194 Dec 22 22:40 2001 String.h
    bash$ tar -xvf ppass1.tar
    String.cc
    String.h
    bash$ ls
    String.cc  String.h  ppass1.tar
    

Using the submission system

• Listing assignments
  
  • To list all the assignments available for submission, you can use the command:

    givelist
    

  • For example,

    bash$ givelist
    Name               Sufx Category Until            Cse Description
    
    comp2004s.a0       .tar ontime   Wed Jan  9 17:00     Adder
    comp2004s.a1       .tar ontime   Mon Jan 14 17:00     Roman Numeral Converter
    

  • To list more details about a particular assignment, you can use the command:

    givelist assignment
    

    where assignment is the name of the assignment. You can list assignments which aren't active (ie. which don't show up in a normal givelist command).

  • For example,

    bash$ givelist comp2004s.a2
    
    Name:           comp2004s.a2
    File suffix:    .tar
    Description:    Calendar System
    Start date for assignment: Tue Jan 15 00:00.
    
    Due dates and their categories are:
    
                         ontime     Fri Jan 25 17:00
                         late       Fri Jan 25 17:05
    
    

• Submitting a file
  
  • To submit a file for an assignment, you can use the command:

    submit file assignment
    

    where file is the name of the file to submit, and assignment is the name of the assignment to submit to.

  • For example,

    submit ppass1.tar comp2004s.a1
    

  • You can resubmit as many times as you like before the deadline. Only your most recent submission will be kept. Once the deadline passes, you can't make any submission or resubmission.

  • You should plan to have something submitted when the deadline arrives, since you can always replace what you have submitted with a newer version simply by resubmitting before the deadline. If you miss the deadline, it's much better to have an old version of your code marked than nothing at all.

• Retreiving a submitted file
  
  • To retreive your submission for an assignment, you can use the command:

    givepeek assignment > file
    

    where assignment is the name of the assignment to retreive, and file is the filename into which a copy of your submission should be placed. If it already exists it will be deleted.

  • For example,

    givepeek comp2004s.a1 > ppass1-submitted.tar
    

  • This is useful to make absolutely sure your submission is how you think it is. To get an exact copy of what's been submitted, use the following commands (or a similar variation):

    mkdir ppass1-submission
    cd ppass1-submission
    givepeek comp2004s.a1 > ppass1.tar
    tar -xvf ppass1.tar
    

    and you will now have a directory called ppass1-submission which contains your submitted tar file in ppass1.tar and all of the files inside that tar file. You could now test the compilation by running g++ -Wall -g -c String.cc or make or whatever command is appropriate.